Nitrate derivatives are useful drugs because of their direct vasodilating properties even in the presence of abnormal endothelial function. This is particularly true of the great arteries, explaining the improvement in arterial compliance regularly observed. The corollary of this effect is an improvement in systolic blood pressure and arterial pulsatility with little change in mean arterial pressure. The improved systolic but unchanged mean blood pressures reduce myocardial systolic stress and ensure relative preservation of coronary perfusion pressure which is particularly important in the treatment of systolic hypertension of the elderly.